Conversion of hydrocarbons



Juiy 24, 1934-. P, FElLER ET AL 1,967,665

CONVERSION OF HYDROCARBONS Filed May 18. 1931 2 Sheets-Sheet 1 Pa 1/ fiz 6/" Hans /'/a 6056 INVENTOR5 ATTORNEYQ- July 24, 1934. P. FEILER ET ALCONVERSION OF HYDROCARBONS 2 Sheets-Sheet 2 Filed May 18 1931 #VDROCARGO/V5 IDM I TI'A'D DUCT-5 035070 50 iNVENTORS BY QW M ATTORNEYSPatented July 24, 1934 UNITED STATES CONVERSION OF HYDROOARBONS 1 PaulFeller and Hans Haeuber, Ludwlgshafen-onthe-Rhine, Germany, assignors toI. G. Fan-benindustrie Aktiengesellschal't, Frankfort-on-the- Main,Germany Application 6 Claims.

This invention relates to improvements in the thermal conversion ofhydrocarbons and especially conversions in the gaseous phase, whichexpression also includes the vaporous phase in reaction chambersprovided with fillers, and in apparatus for carrying out the saidconversion.

We have found that the thermal conversion of hydrocarbons in reactionchambers provided with fillers is carried out with considerably better10 yields of the desired reaction products than was hitherto possible bymaintaining the same linear velocity of flow of the said hydrocarbonsover all parts of the surfaces of the fillers and by avoiding thepresence in the path of the flowing hydrocarbons of surfaces, whichwould exercise a baffling action.

This is effected by arranging the fillers regularly and by providingregular channels between the said fillers, which channels should be ofapproximately the same diameter throughout and by avoiding sharp bendsin the said channels. The said channels; are advantageously straight andpreferably pass throughout the whole of the reaction chamber.

In this manner irregular flowing and congestion giving rise to localoverheating ofthe reaction products, such as was liable to take place inthe arrangements hitherto employed, in which the filling bodies werecharged irregularly into the reaction chamber or in which the flowinghydrocarbons encountered sharp bends, are entirely avoided. Also thedeposition of carbon in the form of soot on the fillers is substantiallyavoided in accordance with the present invention,

even if the process be carried out at very high temperatures above 900or 1000 C. or more.

' The channels between the filling bodies may have the'shape ofcylindrical bores, rectangular shafts or prisms. If desired the fillingbodies may 40 be entirely in one piece and the said channels may bebored therethrough.

In order to avoid congestion of the gases in the reaction chamber withgreater certainty, it is advantageous to arrange the filling bodies infront of and behind the reaction zone in the same way as in the reactionzone itself. In this manner an unhindered passage of the substances tobe treated and a rapid withdrawal of the reaction products is ensured.

The filling bodies may be supported by a grate, which is also preferablymade of such a'shape as toavoid the setting up of congestions in theflow of the materials undergoing treatment. Preferably the openings inthe grate should have a similar shape to that of the channels. Thefilling May 18, 1931, Serial No. 538,190 Germany June 17, 1930 bodiesmay also be hung up in the reaction chaniber with the aid of a suitablesupport arranged at the top of the reaction vessel.

Furthermore, it has been found to be advantageous to provide the partsof the reaction cham- 5o ber, which come into contact with the gases orvapours, especially the filling bodies and the walls, with surfaceswhich are as smooth as possible, as for example, by glazing, becausethis precaution also contributes to the avoidance of undesirabledeposits of carbon. In many cases itis even preferable to employ afilling having highly polished surfaces.

The special arrangement and nature of the filling bodies according tothis invention are suit- 7 able when working under any pressure and forcontinuous or periodic operation.

The said filling bodies may be constructed of a material capable ofretaining large amounts of heat as for example chamotte. They mayfurther be constructed of materials exercising a catalytic action as forexample silicon or silicon carbide or materials containing these ifdesired together with binding agents such as clay.

The process is applicable to the cracking or destructive hydrogenationof hydrocarbons in the liquid, but more especially in the gaseous orvaporous phase particularly in the production of aromatic hydrocarbonsaccording to the said processes, to the conversion of gases comprisingmethane or its homologues or gases containing these into olefines andother hydrocarbons such as benzene and its homologues, or to theproduction of hydrogen and gases containing hydrogen from hydrocarbonsby treatment of these hydrocarbons with water vapor or oxygen or gasescontaining free oxygen such as air or carbon dioxide or mixtures ofthese gases.

Where it is desirable, diluent gases such as nitrogen may also bepresent in the said process. This may prove advantageous where areduction of the partial pressure of the initial hydrocarbons isdesirable as in the production of olefines or of diolefines.

Figures 1 and 2 of the accompanying drawings represent vertical sectionsof reaction chambers very suitable for carrying out the beforedescribedconversion of hydrocarbons. Figure 3 shows a horizontal cross sectionalong line X-X of Figure 1. Figures 4, 5 and 6 show horizontal crosssections of other arrangements of the fillers. Figures 1 and 2 are withreference to the following examples which will further illustrate thenature of this invention, but the invention is not restricted to theseexamples.

Example 1 A reaction chamber about 6 meters in height and about 26centimeters broad and lined with chamotte is filled with well polishedchamotte plates A as shown in Figure 1 which are 1 centimeter apart insuch a way that shaft-shaped channels B pass through the whole reactionchamber. If 1 cubic meter of a gas containing 90 per cent methanebe'passed through the reaction chamber heated to about 1100" 0., about35 grams of liquid hydrocarbons consisting to the extent of '70 per centof benzene are obtained smoothly without any deposition of soot.

If, on the contrary, a chamber irregularly filled with pieces ofchamotte be employed under the same conditions considerable deposits ofsoot are noticed at those places at which a congestion of the gas takesplace. Moreover the reaction gas contains more hydrogen than in theformer case.

Example 2 This example is with reference to Figure 2. Cube shaped bodies0 (the length of the edges being from about 8 to 10 millimeters)prepared of nitrogen and also some butylene, propylene,

ethylene, methane and hydrogen is preheated to about 440 C. and thenpassed at the rate of 850 liters per hour and under a pressure of 50atmospheres through the said tube heated for 500 millimeters of itslength to about 550 C.

1200 liters per hour of a gas mixture are obtained which contains 2.6per cent by volume of butane, 10.4 per cent of propane, 17.8 per cent ofethane, 15.7 per cent of nitrogen, 37.6 per cent of methane and alsobutylene, propylene, ethylene and hydrogen. Furthermore, 95 grams ofliquid hydrocarbons which are composed of saturated and unsaturatedaliphatic hydrocarbons may be condensed from each cubic meter of gasesor vapors leaving the reaction vessel. 40 per cent or thesehydrocarbons, which are suitable for example for the preparation offuels and lubricating oils, boil up to 120 C. and 70 per cent boil up to270C. The conversion of the hydrocarbons in the said manner proceedswithout the deposition or soot.

What we claim is:

1. In the production of aromatic hydrocarbons by thermal conversion ofgaseous hydrocarbons which comprises effecting the conversion whilepreventing deposition of carbon by passing said gaseous hydrocarbons,while under a temperature suitable for the conversion, at a uniformvelocity through a reaction space having a plurality of straight,unobstructed and similar passages extending longitudinally throughoutthe entire length of said reaction space and defined by walls comprisingessentially a material selected from the class consisting of chamotte,silicon and silicon carbide.

2. The process as defined in claim 1 wherein said passages havesubstantially the same crosssectional area.

3. The process as defined in claim 1 wherein said conversion is efiectedat a temperature ranging between about 900 and about 1100 C.

4. The process as defined'in claim 1 wherein the surfaces of saidpassageways are substantially 5 smooth.

5. The process as defined in claim 1 wherein said initial hydrocarbonsare normally gaseous hydrocarbons.

6. In the production of aromatic hydrocarbons 110 by thermal conversionof gaseous hydrocarbons which comprises effecting the conversion whilepreventing deposition of carbon by passing said gaseous hydrocarbonswhile under a temperature suitable for the conversion, at a uniformvelocity 5 through a reaction space having a plurality of straight,unobstructed and similar passages extending longitudinally throughout.the entire length of said reaction space and defined by walls comprisingessentially a refractory material.

PAUL FEILER. HANS HAEUBER.

